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ZHANG, R.

Publications and source records attributed to ZHANG, R..

3 recordsLinked to original sources

Cell-type specific allelic dampening of sex-linked genes in sex chromosome aneuploidy

Common sex chromosome aneuploidies (SCAs) often present with cognitive and cardiovascular dysfunction in humans. To address SCA effects on gene expression and DNA methylation in relevant cell types, we differentiated neural precursor cells (NPCs) and cardiomyocytes (CMs) from human induced pluripotent stem cells (hiPSCs) with different numbers of sex chromosomes, including isogenic and independent lines. As expected, the expression of genes that escape X inactivation (escapees) mostly increases with the number of inactive X chromosomes (Xi). However, allelic analysis shows dampening of escapees specifically on the Xi in XXY compared to XX in both NPCs and CMs, revealing a novel type of dosage compensation in SCA. In contrast, Y-linked gene expression is higher in XXY versus XY NPCs, but the opposite is observed in CMs. This may explain the greater number of differentially expressed autosomal genes in NPCs versus CMs with an added Y chromosome, while effects of added X chromosomes are similar between cell types. Concordantly, changes in autosomal DNA methylation are mainly driven by the presence of a Y chromosome. These findings highlight the cell-type specificity of sex-linked and autosomal gene regulation in SCA conditions. HighlightsO_LISex chromosome aneuploidy induces cell-type specific changes in gene expression C_LIO_LIDampening of the inactive X chromosome in XXY alleviate X overexpression C_LIO_LIHigh Y-linked gene expression in XXY neuronal precursor cells but not cardiomyocytes C_LIO_LISex chromosome aneuploidy disrupts sex biases in autosomal gene expression C_LI

molecular biology↗

TSPAN1 promotes human pancreatic cancer cells proliferation by modulating CDK1 via Akt

BackgroundTo explore the potential therapeutic target to treat pancreatic cancers, Tspan1 was detected in human pancreatic cancer tissue and human pancreatic ductal adenocarcinoma cells and functional role of Tspan1 on proliferation was explored and the mechanism was investigated. Materials and MethodsTspan1 in PCC tissue and PDAC cell lines was measured by qRT-PCR and Western blot. Tspan1 was knock-downed and over-expressed in cells via transfection with Tspan1-siRNA and pLNCX-TSPAN1-cDNA, cell survival, proliferation and cell cycle were measured with MTT, Alamar blue and Flow Cytometry assay. The mRNA and protein expression were assessed by qRT-PCR and Western blotting. The expression of PI3K, Akt and p-Akt were detected, and CDK1 siRNA and specific inhibitor of Akt were used to explore the mechanism of TSPAN1 promoting PDAC cells proliferation. ResultsTspan1 expression in PCC tissue and PDAC cells was increased. Transfection of siRNA targeting Tspan1 in BxPC3 and PNAC-1 cells obviously decreased cell proliferation and down-regulated CDK1 expression. Consistently, both cell proliferation and CDK1 expression in BxPC3 and PNAC-1 cells were up-regulated with pLNCX-TSPAN1-cDNA transfection. Cell cycle analysis showed that after knockdown of Tspan1 the G2/M phase ratio was increased to cause mitosis arrest, and TSPAN1 overexpression caused cell cycle transition from G2 to M phase to promote cell proliferation. And these were dependent on the modulation of CDK1 expression via Akt. ConclusionTspan1 up-regulates CDK1 expression via activating Akt to promote human PCC cell proliferation and silencing of Tspan1 may be a potential therapeutic target to treat pancreatic cancers.

molecular biology↗

The Cupin Protein, Dehydratase Pac13 is a Homodimer

Cupin proteins share a double-stranded {beta}-helix fold, form one of the largest superfamilies and possess remarkable functional diversity. They usually form homooligomeric states. Michailidou et al. recently reported that a cupin protein Pac13, which is a dehydratase mediating the formation of the 3-deoxy nucleoside of pacidamycins, is an unusual, small monomer. However, a careful analysis of the biophysical and structural data provided by the authors clearly indicates that Pac13 is a homodimer.

biochemistry↗